All You Need To Know About Furnace Ignition Lockout

All You Need To Know About Furnace Ignition Lockout

A furnace faces several problems during its working lifespan. Most furnace owners know the common problems related to their furnaces, like dirty air filters and clogged vents. However, one of the problems that most furnace owners do not know about is the furnace ignition lockout.

As the name suggests, a furnace ignition lockout is a situation in which the safety sensors of your furnace do not allow it to start functioning. When the safety sensors detect a threat, they turn the furnace off to avoid any hazards. Contact LAC Heating & Air for heating services in Pasadena, CA, for assistance.

Causes Of A Furnace Ignition Lockout


  • Flame Sensor

The primary function of a flame sensor is to detect the presence of a flame inside the furnace. If it malfunctions, the furnace will not detect a flame, and the controller will stop the gas flow. The furnace will restart twice or three times before it goes into lockout.

  • Ignitor

The primary function of the ignitor is to create the initial spark to burn the gas inside the furnace. Its malfunctioning leads to no spark, and the process follows the same as with the flame sensor. You should contact our technician for heating services in Pasadena, CA if the igniter troubles you often.

  • Limit Switch

One of the primary reasons to keep your air filters clean is to ensure the limit switch does not flip. Poor air circulation can flip the limit switch, due to which the furnace will go into lockout. You may locate the limit switch with the help of the user manual.

Troubleshooting Tips For A Furnace Ignition Lockout


Before you contact our technician for heating repair services in Pasadena, CA, you should try some troubleshooting tips for a lockout. You may be able to fix the problem yourself without contacting a professional. You can also save money in the process.

  • Firstly, you should turn off the main power supply to your furnace. It is one of the basic safety steps you should follow before you work on your furnace. If you have any safety equipment like rubber gloves, wear them.
  • Locate your furnace’s flame sensor, take it out, and clean it thoroughly. Cleaning will fix the issue if the flame sensor is why the lockout happened.
  • Since you are already working on your furnace, you may as well replace the air filters. Dirty air filters are responsible for several problems, like poor indoor air quality and dust damage.
  • Moreover, you should check your pipes and vents for blockages. Not only can these blockages cause ignition lockout, but also they can trigger several other issues.
  • Once you finish these steps, you can restart your furnace.



Although these tips should help you restart your furnace, they may not guarantee results each time. In such cases, you should have a trustworthy HVAC technician with you for heating repair services in Pasadena, CA, such as LAC Heating & Air.

You can trust LAC Heating & Air to provide the best HVAC services in Pasadena and surrounding areas. We take pride in our services and ensure complete transparency. Contact us at (562) 600-4311.


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